AbstractA Swiss SME offers simulation services regarding self-organized communication networks to SMEs and industry, but also regulatory authorities. The advantage is to assess performance in plenty of scenarios that are often hard or impossible to test in the real world. Discover pitfalls, evaluate alternatives, probe extreme scenarios and identify reasons of problems well before production or delivery. The concept has been effectively applied to an aircraft anti-collision warning system.
Designing, evaluating, and improving protocols for wireless communication networks can be a complex and difficult task, especially if the communication cannot be governed from a central place (a "server"), or mobile devices are involved. Mobile devices need to "connect" to other devices depending on their location, yet their radio emission may interfere with other devices in range. In a network without a server, the devices need to organize themselves in an effective, peer-to-peer way. This is sometimes called swarm communication.
Such situations occur for example in collision-warning systems of aircraft, wireless computer networks, or cellular phone systems. Moreover, mastering such situation would enable great new opportunities, such as using devices as a relay or repeater for extended range.
The fundamental problem is also present in cable-bound communication, but it is much easier to handle by restraining to simple network topologies.
The present technology offer “simulation of wireless communication” addresses the problem by transferring it to the virtual world, where:
- ideas and concepts can be tested more easily and quickly than in the real world,
- testing scenarios can be automatically generated in large amounts, without manufacturing devices and distributing them in an experimental setup,
- test results can be obtained, collected, and analyzed in an automated and streamlined way.
Moreover, the development process can be greatly supported by simulation as potential problems can be identified in much more detail.
A common digital receiver will simply report success if an incoming digital message could be correctly decoded. If no message or two or more interfering messages were present, the receiver would only report "no message". A more detailed statement would require extra test instrumentation, which also may interfere with the test itself - unlike a simulated experiment, where these incidents can be recorded in detail, including the relative overlap of messages and relative signal strengths. In this way, the development can be guided on improving the timing separation of the communication protocol, or improving the discrimination between weak and strong incoming message in the receiver hardware.
Why simulation of communication protocols?
Simulation of communication protocols is especially suited because the underlying physical, electronic, and protocol characteristics are usually sufficiently known, and no or few assumptions and simplifications are required when building the computer simulation model.
The technology is also suited for testing new or enhanced applications prior to development, and to conduct and guide development as a technical consultancy. The technology is designed to be flexible to be adapted to specific needs. It may also serve as a quality control by comparing theoretical to practical performance, and extrapolate performance from laboratory to real-word scale.
The concept and underlying simulation software has been successfully applied to evaluate and improve the performance of the communication protocol of a widespread anti-collision aircraft warning system commonly used in glider planes in Europe.
- communication performance can be evaluated without the corresponding real experimental setup.
- a wide set of alternatives can be investigated and compared to each other.
- The nature of the communication is recorded in itself: no extra test equipment or measuring instrumentation is required.
- The tests are non-intrusive and non-destructive.
- Reasons of problems can be named and potential improvements can be identified.
- virtual experiments can be repeated in a deterministic way, thus investigating more details or aspects discovered earlier.
- The technology is also applicable to other complex problems, not only communication networks.
- Speculative potential communication protocols can be tested prior to implementation.
- A vast amount of scenarios can be screened in order to find critical singular cases, and to find average behaviour over a representative entirety.
- Scenarios can be automatically generated randomly and following specified guidelines.
- Scenarios may include dangerous, extreme, critical and expensive cases without taking the corresponding real risk.